Used extensively as a fluorescent labeling reagent in biochemical and cellular studies. It is particularly valuable for tagging proteins, peptides, and antibodies due to its reactive succinimidyl ester group, which forms stable amide bonds with primary amines. This compound is widely applied in fluorescence microscopy, flow cytometry, and fluorescence-based assays to track and visualize biomolecules in live or fixed cells. Its high quantum yield and pH sensitivity make it suitable for monitoring cellular processes, such as endocytosis, membrane dynamics, and intracellular pH changes. Additionally, it is utilized in molecular biology for labeling nucleic acids and in diagnostic applications for developing fluorescence-based detection systems.